257Roberts & 117 Seirra GamesKing SPBT

B.Ruddick

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Anyone use the Sierra GamesKing 117g Soft Point Boattails in their 257Roberts?
I've been using 43.5g IMR 4350 w/Hornadys 117g R/N out of a 22"pipe for a few years now, but looking to flatten out the trajectory somewhat.

Some recipes would be much appreciated
 
Accuracy Load H4350EXT, 38.5gr @2600fps MAX LOAD! starting load is33.4gr Hunting Load Reloader 22, 42.1gr@2700fps, 43.9gr is MAX@2800fps, starting load is 34.9gr, IMR 4350, starting load is 31.2gr@2300fps MAX load is 41.2gr@2800fps
 
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I have seen guys trying to push the Roberts to velocities that did not make sence to me, and sure enough they failed! Seems like the roberts just will not go over the 2600-50s fps mark no matter how hard you try to push it?
 
Have a look at Hodgdon's Loading Data ...

Don't have a chrono, but will be trying Hodgdon's Hybrid 100V
with 115 gr. Partitions. Velocities for the "257 Bob" are 3050fps
for their max loads in a 24 inch bbl with this powder.
I would expect 22" bbls might turn up 2900 fps plus.
 
I have seen guys trying to push the Roberts to velocities that did not make sence to me, and sure enough they failed! Seems like the roberts just will not go over the 2600-50s fps mark no matter how hard you try to push it?

Such a crock!! I have had a lot to do with the Roberts, and seldom settle for less than 2950 with the 115-120 grain bullets in a 1-10" twist. My best one was a 24" M700 Classic, that with Reloder 22 and the 115 Partition, would go 3060, and shoot bugholes. With that load I shot Deer [muleys & whitetails] moose, elk and a host of lesser game like coyotes and wolves. Brass lasted forever, and not a sign of excess pressure. Regards, Eagleye.
 
Sorry eagleye you are correct, I never read my post after and did not catch my tipo and I did infact mean 2900-50 with 120s. And really to date i never seen one myself bust 3000 fps thats being honest

Now that being said 3060 is hummen along almost at AI velocities. You must have a fast barrel. Beacuse your right up there!
 
I've been shooting 115 TSX's in an 257 Ackley in a 24" Gaillard barrel the most accurate was 48.5 gr RL-22 at 2900fps,with normal case expansion. Any increase in powder results in a loss of accuracy, the velocity goes up to 3050 fps then goes down again. The decrease in velocity and increase in powder gives more than normal case expansion (unsafe). I had the same results with other bullets in different grain weights. 3060fps in a standard Roberts is a serious hotrod load, thats getting into max velocity in a 25-06. Hope you are using a micrometer, what was the load you used to attain these velocities. ps the 115TSX is a one shot zapper on deer
 
B.Ruddick, I use the same load in my BLR and it works great.
I have some 117 gr. PSPs and have not yet tried them.
I will let you know when I do. My Ruger loves 100gr. bullets of any type and IMR4350.
257Roberts
 
I've been shooting 115 TSX's in an 257 Ackley in a 24" Gaillard barrel the most accurate was 48.5 gr RL-22 at 2900fps,with normal case expansion. Any increase in powder results in a loss of accuracy, the velocity goes up to 3050 fps then goes down again. The decrease in velocity and increase in powder gives more than normal case expansion (unsafe). I had the same results with other bullets in different grain weights. 3060fps in a standard Roberts is a serious hotrod load, thats getting into max velocity in a 25-06. Hope you are using a micrometer, what was the load you used to attain these velocities. ps the 115TSX is a one shot zapper on deer

It may be a serious "hotrod" load in some 257 Roberts, but was definitely not in mine. AAMOF, I went 2 full grains above the load that chronographed 3060 before I was able to measure additional case head expansion that rang the danger bell. [.0007"] As I said, Brass lasts forever, primer pockets do not open, even after 8 or more firings. However, as in any recipe, there are caveats. My rifle: M700 Classic Remington [long action] Barrel: 24" Shilen Supermatch C-M, 1-10" twist. The chamber/throat is cut to allow the 115 Partition to be seated out so the base of the bullet is even with the juncture of neck and shoulder of the case, and allowing .020" jump to the lands. Load is 50.0 grains of Norma MRP [Reloder 22 gives similar results] fired by the WLR primer in a Winchester case only! I have found that most other cases are of lesser internal capacity, and can give pressure signs at this level. Note! I am NOT recommending this load as a safe load in anyone's Roberts. Work up carefully and safely to a max working load in your rifle! Regards, Eagleye
 
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